Robust Control for Islanded DC Microgrids with Nonlinear Loads by Employing Dynamic Tubes
摘要
This chapter builds upon the already developed results, by utilizing information that was omitted in the previous chapters; namely the exact knowledge of the nominal, i.e. uncertainty-free, part of the system dynamics. Following a rigorous control-theoretic approach, it is shown that by incorporating the knowledge of the nominal state trajectory in the control law, similar results can be achieved regarding the system resilience, while substantially improving the transient performance. The developed methodology overcomes the conservativeness in considering a worst-case scenario and shows how a dynamic evolution of the constraint set can achieve faster convergence to the desired equilibrium, when compared to the previous methods. When the proposed control scheme is applied to a microgrid system with constant power loads, simulations of the closed-loop system show that it is possible to achieve overcurrent and overvoltage protection of the power converters, even during transients caused by fluctuations of the load demand.